MYD13C1 v061

MODIS/Aqua Vegetation Indices 16-Day L3 Global 0.05 Deg CMG


PI: Kamel Didan

Description

The MYD13C1 Version 6.1 product provides a Vegetation Index (VI) value at a per pixel basis. There are two primary vegetation layers. The first is the Normalized Difference Vegetation Index (NDVI) which is referred to as the continuity index to the existing National Oceanic and Atmospheric Administration-Advanced Very High Resolution Radiometer (NOAA-AVHRR) derived NDVI. The second vegetation layer is the Enhanced Vegetation Index (EVI), which has improved sensitivity over high biomass regions.

The Climate Modeling Grid (CMG) consists 3,600 rows and 7,200 columns of 5,600 meter (m) pixels. Global MYD13C1 data are cloud-free spatial composites of the gridded 16-day 1 kilometer MYD13A2 data, and are provided as a Level 3 product projected on a 0.05 degree (5,600 m) geographic CMG. The MYD13C1 has data fields for NDVI, EVI, VI QA, reflectance data, angular information, and spatial statistics such as mean, standard deviation, and number of used input pixels at the 0.05 degree CMG resolution.

read more

Characteristics

Improvements/Changes from Previous Versions

  • The Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 - 2017.
  • A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).

Product Maturity

Validation at stage 3 has been achieved for the MODIS Vegetation Index product suite. Further details regarding MODIS land product validation for the MYD13 data products are available from the MODIS Land Team Validation site.

Collection and Granule

Collection

Characteristic Description
CollectionAqua MODIS
DOI10.5067/MODIS/MYD13C1.061
File Size~99 MB
Temporal ResolutionMulti-Day
Temporal Extent2002-07-04 to Present
Spatial ExtentGlobal
Coordinate SystemGeographic Latitude and Longitude
DatumN/A
File FormatHDF-EOS
Geographic DimensionsGlobal

Granule

Characteristic Description
Number of Science Dataset (SDS) Layers13
Columns/Rows7200 x 3600
Pixel Size5600 m

Layers

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
CMG 0.05 Deg 16 days NDVI 16 day NDVI NDVI 16-bit signed integer -3000 N/A -2000 to 10000 0.0001
CMG 0.05 Deg 16 days EVI 16 day EVI EVI 16-bit signed integer -3000 N/A -2000 to 10000 0.0001
CMG 0.05 Deg 16 days VI Quality VI quality indicators Bit Field 16-bit unsigned integer 65535 N/A 0 to 65534 N/A
CMG 0.05 Deg 16 days red reflectance Surface Reflectance Band 1 N/A 16-bit signed integer -1000 N/A 0 to 10000 0.0001
CMG 0.05 Deg 16 days NIR reflectance Surface Reflectance Band 2 N/A 16-bit signed integer -1000 N/A 0 to 10000 0.0001
CMG 0.05 Deg 16 days blue reflectance Surface Reflectance Band 3 N/A 16-bit signed integer -1000 N/A 0 to 10000 0.0001
CMG 0.05 Deg 16 days MIR reflectance Surface Reflectance Band 7 N/A 16-bit signed integer -1000 N/A 0 to 10000 0.0001
CMG 0.05 Deg 16 days Avg sun zen angle View zenith angle of VI Pixel Degree 16-bit signed integer -10000 N/A -9000 to 9000 0.01
CMG 0.05 Deg 16 days NDVI std dev Standard deviation computed from input NDVI pixels NDVI 16-bit signed integer -3000 N/A 0 to 10000 0.0001
CMG 0.05 Deg 16 days EVI std dev Standard deviation computed from input EVI pixels EVI 16-bit signed integer -3000 N/A 0 to 10000 0.0001
CMG 0.05 Deg 16 days #1km pix used Number of 1 km input pixels used Number 8-bit unsigned integer 255 N/A 0 to 36 N/A
CMG 0.05 Deg 16 days #1km pix +-30deg VZ Number of 1km pixels used with VZ angle less than + or - 30 degs Number 8-bit unsigned integer 255 N/A 0 to 36 N/A
CMG 0.05 Deg 16 days pixel reliabilty Quality reliability of VI pixel Rank 8-bit signed integer -1 N/A 0 to 4 N/A

Product Quality

The "CMG 0.05 Deg 16 days VI Quality" layer is stored in an efficient bit-encoded manner. The unpack_sds_bits executable from the LDOPE Tools is available to the user community to help parse and interpret the quality layer.

The QA bit flags for the "CMG 0.05 Deg 16 days pixel reliabilty" layer are provided in Table 18 and the "CMG 0.05 Deg 16 days VI Quality" layer in Table 5 and 17 of the User Guide.

Known Issues

For complete information about known issues please refer to the MODIS/VIIRS Land Quality Assessment website.

Documentation

User Guide
Algorithm Theoretical Basis Document (ATBD)
File Specification

Using the Data

Access Data

Citation

DOI: 10.5067/MODIS/MYD13C1.061

About the Image

Aqua MODIS NDVI data from the MYD13C1 product across the globe, July 19 - August 3, 2020.

View full-size image